Upon outputting a high-quality image based on image data via a printer or display, a plurality of objects that form the image must undergo color processes such as color correction, color conversion, binarization, and the like in correspondence with the types of objects.
In general, upon printing or displaying on a display device an image created by application software, rendering commands from the application software are imaged by a device driver (or device itself) of a printer or display device to create image data to be printed or displayed for the entire page. Rendering commands that form a document include, e.g., an image rendering command corresponding to a photo image portion, a text rendering command corresponding to a text portion, and a graphic rendering command corresponding to a graphic portion. Such rendering commands are issued to the device driver, which execute color processes suitable for individual objects in units of types of commands, thus converting the commands into an image that an output device can output.
Upon conversion, color matching processes are switched so that graphics, text, and photo portions respectively undergo “saturation”, “calorimetric”, and “perceptual” processes, and an image in which all objects on the entire page have high image quality can be obtained.
In recent years, some system or application software designates a “source color space” of each object, and the device driver can obtain a high-quality output image using the designated contents. For example, when a scanner input image is pasted onto a document, the image rendering command of that image can designate a color profile which describes the device characteristics of a scanner, or a color profile that describes the characteristics of a monitor used to reproduce colors observed by the editor upon color calibration on the display. Such color profiles are, for example, International Color Consortium (ICC) profiles, and Image Color Matching (ICM) of Windows®95 available from Microsoft Corp., ColorSync of Apple Computer, and the like are known as systems that can use such profiles.
In order to implement the aforementioned image processes, upon printing even an image that the user recognizes as a single image, application software or an operating system often issues a plurality of rendering commands. In this case, whether or not rendering commands corresponding to a plurality of segmented images can be combined is checked by comparing apex coordinate information of rectangular regions as rendering regions of the respective rendering commands corresponding to the plurality of segmented images, as described in Japanese Patent Laid-Open No. 2000-13622.
For example, as shown in FIG. 1, when one image is issued as two image rendering commands, since the lower left apex of rectangular region 1-A of the first rendering command neighbors the upper left apex of rendering region 1-B of the second rendering command, and the lower right apex of rectangular region 1-A also neighbors the upper right apex of rectangular region 1-B, it is determined that images to be rendered by the two rendering commands can be combined.
Recent application software normally has a function of cutting image data into an arbitrary shape. When an image cut using this function is to be printed, a plurality of image rendering commands are issued.
For example, as shown in FIG. 2, these image rendering commands are issued to be segmented into rectangular regions 2-A, 2-B, 2-C, 2-D, and 2-E. When the image is segmented, as shown in FIG. 2, the aforementioned method of checking by comparing apex coordinate information of these rectangular regions if rendering commands corresponding to a plurality of segmented images can be combined cannot determine whether all five image rendering commands corresponding to these cut (segmented) images can be combined. For this reason, these segmented images cannot undergo an identical correction process on the basis of the characteristics (e.g., color distribution) of an image that the user recognizes as a single image, and an image with poor image quality is obtained in place of that with high image quality.